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Abstract:

When a user selects digital zooming in a camera such as might be included
in a wireless telephone or PDA, a series of images are automatically
obtained and superimposed using super-resolution techniques to produce an
improved digital zoom image transparently to the user.

Claims:

1-13. (canceled)

14. Apparatus, comprising: an imager; and a processor configured for
accessing instructions to configure the processor for combining at least
two images derived from signals from the imager to render a modified
digital zoom image from the at least two images, the modified zoom image
having a higher resolution than at least one of the two images; and the
processor when accessing the instructions being configured for sending to
computer storage or to a display the modified digital zoom image, wherein
the processor when executing the instructions renders the modified zoom
image.

15. Apparatus of claim 14, wherein the images are superimposed using
super-resolution.

16. Apparatus of claim 14, wherein the apparatus has no capability for
optical zooming.

18. Apparatus of claim 14, wherein the apparatus is embodied as a
wireless telephone.

19. Apparatus of claim 14, wherein the apparatus is embodied as a
personal digital assistant (PDA).

Description:

FIELD OF THE INVENTION

[0001] The present invention relates generally to improving the image
quality during digital zoom in cameras without optical zoom capability.

BACKGROUND OF THE INVENTION

[0002] Optical zooming in camera entails the translational moving of a
lens to magnify the image. In less capable cameras such as those
typically included in wireless telephones and personal digital assistants
(PDAs), the lenses do not move. To provide for a zoom-like function,
digital zooming is used in which, for example, a portion of the image is
cropped and the remaining image simply enlarged to fill the image screen.
As understood herein, white digital zooming simulates the magnification
yielded by optical zooming, it reduces image quality compared to optical
zooming.

SUMMARY OF THE INVENTION

[0003] A method includes receiving a user selection of digital zooming in
a camera and in response automatically generating plural images. The
images are digitally zoomed and then superimposed to produce an improved
digital zoom image transparently to the user.

[0004] The superimposition may be undertaken using super-resolution. The
camera can be incorporated into a wireless telephone or personal digital
assistant (PDA) or other device that does not have optical zoom
capability. if desired, prior to zooming the images a portion of each
image can be removed to render respective cropped images, and the cropped
images are digitally zoomed.

[0005] In another aspect, an apparatus includes an imager, a processor
communicating with the imager to receive signals therefrom, and a
computer readable medium accessible to the processor and bearing
instructions. The instructions cause the processor, in response to a
predetermined user command to generate at least two images automatically
and digitally zoom each image to render a respective zoomed image. The
instructions also cause the processor to superimpose the zoomed images on
each other to render a modified zoomed image.

[0006] In still another aspect, an apparatus includes an imager, a
display, and a processor configured to present on the display a modified
digital zoom image including at least two superimposed images.

[0007] The details of the present invention, both as to its structure and
operation, can best be understood in reference to the accompanying
drawings, in which like reference numerals refer to like parts, and in
which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a perspective view of a non-limiting device that can
incorporate present principles, with some components shown schematically;
and

[0009] FIG. 2 is a flow chart of non-limiting logic in accordance with
present principles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] Referring initially to FIG. 1, an apparatus is shown, generally
designated 10, that can include an imager 12 such as a charge coupled
device (CCD) and a processor 14 receiving image signals from the imager
12. The processor 14 can access a computer readable storage medium 16
such as but not limited to removable or non-removable solid state memory,
disk memory, etc. The logic of FIG. 2 may be embodied as computer
instructions on the medium 6 that are executable by the processor 14 to
present a digitally zoomed image on a display 18 in accordance with
principles set forth below.

[0011] The apparatus 10 may be embodied as a wireless telephone or
personal digital assistant (PDA) or other portable device with a portable
housing 20 in which, in one embodiment, the display 18 may be hingedly
coupled to a base 22. The base 22 can be bear an input device 24 such as
a telephone keypad, and one or more controls 26, both of which generate
input signals to the processor 14 when manipulated. Among the user
commands that can be input is a "digital zoom" command. The apparatus 10
may not have optical zoom capability. A wireless telephony receiver 28
may also be incorporated in the apparatus 10.

[0012] Now referring to FIG. 2, at block 30 a predetermined command from
the user such as a digital zoom command is received. The command may be
generated by, e.g., manipulating the control 26. In response, at block 32
plural images from the imager 12 are captured automatically in quick
succession, e.g., within a few seconds of receiving the command. This
occurs automatically, transparently to the user.

[0013] In some embodiments a portion of each image is removed from the
image to render a cropped image at block 34. The cropped images are
digitally zoomed at block 36 by, e.g., expanding the remaining image
pixels to fill the original image area. Then, the zoomed images are
combined at block 38 by superimposing them on each other to render a
modified zoomed image that has higher resolution than any of the images
from which it is derived. In one implementation, the superimposition may
be done using super-resolution principles such as those disclosed in,
e.g., U.S. Pat. Nos. 6,208,765 and 7,218,751, incorporated herein by
reference. The modified zoomed image is presented on the display at block
40.

[0014] As understood herein, if super-resolution techniques are used that
require relative motion between successive images, this requirement may
be satisfied by the inevitable hand movement that occurs when a person
holds a camera, which results in a sequence of images in a few seconds
each of which is slightly different than the others. If motion
calculation is required, motion estimation algorithms may be employed.
For example, a simple algorithm might be to estimate motion using groups
of pixels in each image that remain substantially unchanged in value
except for their relative positions within the images, with motion
vectors being derived directly from the motion of the groups of pixels
from image to image. The super-imposition techniques may use Bayesian or
Kalman filtering techniques in rendering the final, modified zoomed
image.

[0015] The super-resolution processing may be executed in near real-time
by the processor 14 as described above, or the images captured at block
32 and cropped at block 34 may be stored in the medium 16 and later
downloaded to a personal computer or the like for subsequent steps to be
performed off-line to render a final modified high resolution image that
can then be printed or displayed on a large display such as a PC screen
or TV.

[0016] While the particular SUPER-RESOLUTION DIGITAL ZOOM is herein shown
and described in detail, it is to be understood that the subject matter
which is encompassed by the present invention is limited only by the
claims.